Seat occupancy detection is used for a variety of purposes in passenger vehicles. This includes for example the systematic activation of occupant protection systems such as gas bag modules or belt tensioners. Here, on the basis of the differentiation between an occupied and an unoccupied seat, the safety systems can be systematically activated only for the occupied seats in the case of an accident, which saves resources. Another case of application for seat occupancy detection is to serve as one of the detection sensors for monitoring the wearing of a seat belt.
Such units are arranged for example in the seat padding and are activated by loading with the weight of the vehicle occupant.